Method of improving lubricating oil



-Patented June 18, 1940 UNITED STATES PATENT oFFicE Louis A. Mikeska, Elizabeth, N. J., assignor to Standard Oil Development Company, a corporation of Delaware No Drawing. Application September 26, 1936, Serial No. 102,706

18 Claims.

This invention relates to lubricating oils and pertains more particularly to. a process for producing lubricating oil of a better quality and to the product produced therefrom.

This application is a continuation-in-part of my copending application U. S. Ser. No. 635,235,

filed September 28, 1932,

The purpose of lubricating oils is to reduce friction between moving parts. In order to reduce the friction it is necessary for the oil to maintain an unbroken film between the moving surfaces. Moreover, the relative amount of friction loss depends also on the nature of the films formed which varies with different types of oils.

A true measure of a good lubricating oil therefore is its ability to maintain a 'low friction film under the widely varying service conditions. The ability of an oil to maintain .such a film depends on the fluidity or viscosity of the oil, its surface tension, penetrating power, stability, resistance to oxidation and sludge formation, and numerous other factors. For example, for oils employed at low temperatures such as for ice machines, and for winter lubrication of automobiles and other lfl motors. it is essential that the oil have a low pour point in order that it may flow under such low temperature service conditions and thus provide the desired film.

As a further example, in order for the oil to ,0 function properly under a relatively wide range of temperature conditions it is essential that the varying temperature should have relatively little effect upon the viscosity and other properties of m the oil. The relative change in viscosity with cient of anoi] is commonly referred to as its viscosity index. which is determined by the method outlined by Dean and Davisin their article in Chemical and Metallurgical Engineering, vol. 0 36. page 618.

Lubricating oils obtained from different types of crudes have widely different properties. For example, oil from paraffin base crude, such as'a Pennsylvania oil, exhibit a relatively high vis- 5 cosity index and consequently are least affected by temperature .change. However, they normally have a relatively high pour point and in many cases are more susceptible to oxidation and sludge formation.

Lubricating oil produced from asphaltic base crude'oils on the other hand have a relatively low viscosity index but are relatively more resista'nt to oxidation and sludge formation and have relatively lower pour point.

, Theobject of the present invention is to produce a lubricating oil of superior quality, which has a low pour point, a high viscosity index, a high resistance to oxidation and sludge formation, and which forms an improved film which temperature or the viscosity-temperature coefii produces a relatively low friction loss between moving parts.

In accordance with'one mode of operating my process I admix with the lubricating oil to be improved, -or to a selected fraction thereof of a nature hereinafter described, a halogenated long chainparaffiln compound. The halogenated long chain hydrocarbon compound is caused to react with the oil, or with certain constituents of said oil in the presence of a condensing agent ofthe Friedel-Crafts type such as aluminum chloride, zinc chloride, boron fluoride or the like. The reaction may be carried out at room temperature if suitable time is allowed, but it is preferred to operate at elevated temperature below active decomposition temperature of the oil, which may be about 350 F. or 400 F.

The reaction may be maintained under atmos- 'pheric or moderate superatmospheric pressure. The condensation may be carried out in an oxidizing atmosphere but greater benefits are obtained if the reaction is accomplished under a non-oxidizing atmosphere such as an atmosphere of flue gas, carbon monoxide, methane, nitrogen or hydrogen. The use of hydrogen improves the color of the final product. Bubbling hydrochloric acid through the reacting mixture gives better color and improved yields. The halogenated long chain hydrocarbon compound may be an alkyl or acyl halide. In the case of the alkyl chlorides the long chain hydrocarbon should contain more than ten carbon atoms to the molecule. When employing acyl chlorides the chain may contain somewhat less than ten carbon atoms particularlywhen it is desired to merely improve the oiliness characteristics of the oil.

It has been found that the acyl halides are particularly advantageous. The condensation product produced by condensing acyl chlorides with the oil, or certain constituents thereof, contain oxygen in the form of a keto group which has been found to be particularly efiective in that in addition to improving the viscosity index and resistance to sludge and oxidation, it materially reduces the friction loss.

The alkyl halides may be produced by direct halogenationof corresponding parafiins such as paraffin wax, petrolatum and the like. When chlorinated wax is used the chlorine may range from 5% to 35% but is most desirable within the range of from to The halogenation is carried out under optimum conditions to produce monohalogen substituted products. Excess wax may be removed'from the finished product in the usual manner. The alkyl halides may also be produced from corresponding alcohols by substituting a halogen in place of the hydroxyl group. This may be accomplished by treatment with hydrochloric acid orby the other acid aid in carrying 'paraflinic raffinate fraction -may be produced from stearic acid by reaction with sulphuryl chloride.

Best results are obtained when the reactive group is at or adjacent to the end of the long chain hydrocarbon for in such case the condensation product is-a straight rather than a branch chain.

It will be understood that the methods of making the long chain hydrocarbon halogenated compounds form no part of the present invention but are disclosed in order to serve as an out my invention.

As before pointed out, the long chain hydrocarbon compound may be admixed with the oil to be improved and caused to condense therewith in the presence of a Friedel-Crafts condensing agent.

It isv preferred, however, to first extract the oil with a selective solvent such as phenol, sulphur dioxide, nitrobenzol or the like, capable of separating the oil into a relatively higher of superior lubricating properties and a non-parafiinic extract frac- 1 tion of inferior lubricating properties. The nonparaffinic extract fraction containing av relatively higher percentage of cyclic compounds are then caused to condensewith the long chain parafl'ln hydrocarbon compound containing the reaction group. The condensate so formed. after separation from any uncondensed material. may be blended with the raffi'nate fraction so separated or with any lubricating oil which it is desired to improve. By this method the improvement is brought about in those fractions having inferior lubricating properties and which need improvement most.

In cases where it is desired to produce an oil having exceptionally high viscosity index coupled'v'vith improved oiliness characteristics the ,raflinate fraction may be caused to condense with the halogenated compound. While the rafiinate fraction is relatively free of aromatic and other ring compounds as compared. with the extract, it nevertheless does contain some ring compounds which may be made'to condense with the halogenated compound. The use of acyl halides when condensing the raifinate is of particular advantage because of its beneficial effect on the oiliness characteristics of the ketonized products formed by the condensation.

As already pointed out, acyl halides and particularly the chlorides such as stearyl-chloride,

for example, are especially valuable as condensation reactants. The condensation product thus produced contains a keto-group which imparts additional benefits to the'lubricating oil.

The acyl halides may be caused to condense 1 with the lubricating oil or a selected fraction .thereofas already described or it may be sepa- ;1'at.e1y condensed with other cyclic or polycyclic :..compounds and the condensation product added .to-the lubricating'oil to be improved. For example, stearyl chloride may be condensed with tetrolin to form heptadecyl-tetralino ketone and this compound may be used as a lubricant or blended with lubricating oil. In the latter casethe blend may contain from 5 to'25 per cent of the ketone and preferably about 10%.-

As a further example, stearyl chloride may be condensed with benzene to form heptadecylphenyl.. ketone and this compound used alone.

' the presence of one or more rings does not bar its use altogether in my process, although, pure ly paraifinic materials are most desirable. For example, I have found that phenyl or naphthyl stearic acid may be converted to the corresponding acyl halide, alkyl halide or olefin and can be caused to react with a low grade oil to considerably increase its viscosity :index. It will be understood that my object is to increase the proportionof the open chain carbon those of the rings and this can be done if the material added to the lubricating oil and caused to react therewith is a material of such structure as to cause such an increase even though it may contain 1 or more rings in its structure.

The following examples are presented to illustrate the use and effect of my methods and to clearly indicate their improvement over the known methods.

Example 1 10% by weight of a chlorinated paraffin wax (chlorine content 31%) is added to a low grade lubricating oil and 10% by weight of aluminum chloride is stirred into the mixture during the course of 10 or 15 minutes. Temperatures are maintained at 100 F. for about 45 minutes during which the mass is vigorously stirred. At the end of this time the reaction product.is cooled and allowed to settle. The clear. oily layer is then drawn off, washed and dried. The yield of the treated oil amounts to about of the original low grade oil. The original and treated oils have the following inspection:

Original Treated Viscosity F seconds Saybolt.. 379 402 Viscosity 210 F .i .do. 49. 4 53. 2 Viscosity inde 0 60 Pour point .F 0 3( "9 Example 2 In an experiment carried out exactly in accorc with No. 1, 15% of chlorinated wax was usec and the viscosity of the product was raised lit 64 seconds at 210 F. with visc'osity index of '71 Example 3 To illustrate the improvement in my methoi over the. well known treatment with aluminum chloride, the original oil of experiment No.

is treated in the same manner except that n chlorinated wax is added. The treated oil he the following specification:

Viscosity 100 F 328 Viscosity 210 F l 4s Viscosity index 31 Example 4 To 100 parts by weight of a low grade lubr eating oil fraction derived from a naphthen base crude an equal volume of heavy naphtha added together with 20 parts by weight of stear chloride and about 6% parts of aluminum chl ride. The reaction, is accomplished in thr hours at room temperature with vigorous stirrir atoms to ,was added are given below:

Blank (no gg stearyl chloride) Viscosity 100 F 343 249 Viscosity 210 F .1 51.8 46. 4 Viscosity index... 71 53 The treated oil was stable, of good color and odor and perfectly satisfactory as a light lubricating oil. It contained a small amount of oxygen, in the form ofketone.

Example 5 by weight ofheptadecylphenyl ketone (A) is added to a refined lubricating oil having an S. A. E. rating of 20. The blended oil was then subjected to friction tests on a General Motors boundary lubricating machine at 100 F. at speeds varying from 100 R. P. M. to 2000 R. P. M. with the following results:

Friction in Friction in 1 Oil inch pounds g 2386' @100R.P.M M

Unblended oil (s. A. E. 20 --..L 4.10 a. 30 Same oil-|-10% (A) a. as 27 9s 100%A 2.85 2.00

Example 6 10% by weight of heptadecyltetralino ketone (B) is added to the same type of oil used in Example 5 and subjected to the same tests with the following results:

Friction in Friction in Oil inch pounds g i a @moR- M a. P. M.

E"ttttit 5-12 186 0 4 c l00% mum? 3.10 2.10

E$ampte 7 washed free of hydrochloric acid, dried and the carbon bisulphide removed. The residual oil was then dissolved in ether and saturated with ammonia to remove free stearic acid as ammonium stearate'. The product was then filtered, dried and the ether removed to form the finished oil. This oil was then tested and found to havethe following properties.

When tested on a friction machine of the type specified in Examples V and VI the ketoni'zed oil was found to have a fiiction of only 3.30 inch pounds at 100 R. P. M. and 3.04 at 2000 R. P. M.

as compared withv 4.10 inch pounds and 3.30 inch pounds respectively for the unketonized oil.

Comparative tests on the original oil and the ketonized oil treated as above gave the following results:

on 0mm Sligh Via/100 r. Via/210 r. v.1.

Originaloil--. 115,84 36.1 385 57.1 101 Treatedoilu 26,20,2l 2.3 485 64.5 104 From the above it will be noted that the oxidation rate, Sligh number and viscosity characteristics of ketonized oil are all materially improved. 1

In addition the load carrying capacity of the oil as determined by the Mougey machine is also improved. Whereas the original oil carried from 14 to 18 weights before seizure, the treated oil carried 20 weights with a friction of only 68 inch pounds.

I am aware that it has heretofore been pro posed to condense aromatic hydrocarbons with chlorinated wax and then blend the condensate product with lubricating oil to reduce its pour point. As distinguished'from this, in the case of the alkyl chlorides I condense directly with the oil or with a solvent extracted fraction thereof and I have found that additional benefits may be obtained by employing acyl halides as distinguished from alkyl halides. 1

Having described the preferred embodiment of my invention and given specific examples thereof, it is understood that it embraces such other modifications as come within the spirit and scope thereof. My invention will be more particularly defined in theaccompanying claims wherein I have attempted to adequately cover my invention, but it will be understood that it is not my intention to unnecessarily limit my invention or dedicate any novel feature thereof.

I claim:

1. A method of improving a naphthenic lubrieating oil which-comprises adding to the oil to be improved a relatively small amount of an acyl halide and. condensing the resulting mixture in the presence of a catalyst of the Friedel-Crafts type. 2. A method of improving a naphthenic lubrieating oil which comprises adding to the oil to be improved relatively small amount of a stearyl chloride and condensing the resulting mixture in the presence of a catalyst of the Friedel- Crafts type.

3. A method of producing improved lubricating oil which comprises solvent extracting a naphthenic base petroleum oil to separate the same into a paraffinic fractionand a relatively non-paraffinic fraction, adding a minor amount of a halogen containing long chain hydrocarbon to said relatively non-parafiinic fraction, condensing the resulting mixture in the presence of a catalyst of the Friedel-Crafts type and adding acondensation, product so formed to the lubricating amounts.

4. A method of producing an improvedlubrieating oil which comprises solvent extracting a naphthenic base lubricating oil to be improved to separate the same into a relatively more paraffinic fraction and a relatively less parafllnic frac-' ing oil to beimproved in viscosity index improvtion, adding a minor amount of a halogen containing long chain hydrocarbon having more than ten carbon atoms to said relatively less par.- aifinic fraction, condensing said mixture in the than 'ten carbon atoms to said relatively nonpara'filnic fraction, condensing the resulting mixture in the presence of a catalyst of the Friedelr aits type and adding a condensation product so formed; to the lubricating oil to be improved in /viscosity index improving amounts sumcient to effect the desired improvement.

6. A method of producing improved lubricating oilwhich ,comprises solvent extracting a naphthenic'base petroleum oil to separate the same into a paraffinic fraction and a relatively nonparafiinip fraction, adding a minor amount of an acyl halide to said relatively non-parafiinic fraction, condensing the resulting mixture in the presence of a' catalyst of the Friedel-Crafts type and adding a condensation product so formed to the lubricating oil to 'be improved iniamounts sufficient to effect the desired improvement in the friction test of said lubricating oil.

'7. A method of producing improved lubricating oil which comprises solvent extracting a naph-' thenic base petroleum oil to separate thesame into a. para-flinic fraction and a relatively non parafl'mic fraction, adding a minor amount of st'earylchloride to said relatively non-paraffinic fraction, condensing the resulting mixture in the presence of a catalystof the Friedel-Craits type and adding a relatively small amount of condensation product so formed to the lubricating oil to be improved in amounts sumcient to effect the desired improvement in the friction test of said lubricating oil. q a

8. A method of producing an improved lubricating oil which comprises solvent extractinga naphthenic base lubricating oil -.to be improved to separate the same into a relatively more paramnic fraction and a relatively less paraflinic' fraction, adding a minor amount 'of an alkyl halide having more than ten carbon atoms to said relatively less paraflinic fraction, condensing said mixture in the presence of a Friedel-Crafts cat alyst and blending a minor proportion of the resulting condensed product with said relatively paramnic fraction to improve the lubricating properties thereof.

9. A method of producing an improved lubricating oil which comprises solvent extracting a naphthenic base lubricating oil to be improved to separate the same into a relatively more parailinic fraction and a relatively less-parafflnic fraction, adding a minor amount of an acyl halide having more than ten carbon atoms to said relatively less parafllnic fraction, condensing said mixture in.the presence of a Friedel-Crafts catalyst and forming a blend containing about to 25% by weight of the resulting condensed product with said relatively parafllnic fraction to improve the lubricating" properties thereof.

10. A method of producing an improved lubricating oil which comprises solvent extracting a naphthenic base lubricating oil to 'be improved to. separate thesameinto a relatively more parafiinic fraction and a relatively less paraflinic fraction, adding a minor amount of stearyl chloride to said relatively less parafiinic fraction,

condensing said mixture in the presence of a Friedel-Crafts catalyst and forming a blend containing about 5 to 25% by weight of the-resu1ting condensed product with said relatively paraflinic fraction to improve the lubricating properties thereof.

11. A method of improving lubricating oil which comprises condensing substantially an eguimolecular proportion ofan acyl halide with a ring structure organic compound in the presence of a Friedel-Crafts catalyst to form a ketonic condensation product and addingsaid product in a relatively small amount to the oil to be improved. 12. A method of improvinglu'bricating oil which comprises condensing substantially an equimolecular proportion of stearyl chloride with benzene in the presence of a Friedel-Crafts condensing "agent to form a ketonic condensation product and blending a relatively small amount of said condensate with the oil to be improved.

13. A lubricating .oil containing a relatively .small amount of a condensation product formed by condensing substantially an equimolecular proportion of an acyl halide having more than ten'carbon atoms withan aromatic compound in the presence of a Friedel-Crafts condensing agent. v

14. A method of improving a naphthenic lubricating oil which comprises adding to a naphthenic oil having a viscosity at least suflicient for motor lubrication a minor quantity of a, compound consisting of a long chain hydrocarbon group and a reactive halogen containing group "and condensing the resulting mixture in the presence of i a catalyst of the Frie'del-Crafts type.

15. A method of improving a naphthenic lubricating oil which comprises adding to a naphthenic oil having a viscosity at least suflicient for motor lubrication a minor quantity of an alkyl halide having more than ten carbon atoms per molecule and condensing the resulting mixture in the presence of a catalyst of the 'Friedel-Crafts type.

16. A method of improving a lubricating oil whichfcomprises condensing in the presence of a Friedel-Crafts catalyst cyclic hydrocarbon molecules with substantially no greater than an equimolecular proportion of aliphatic molecules, each of which consists of an alkyl group attached to a reactive halogen containing group and blending-a relatively small amount of the thus formed condensation product with the lubricating oil to be improved.

17. A method of improving a lubricating oil which comprises condensing in thepresence of a Friedel-Crafts catalyst a naphthenic hydrocarbon with substantially nogreater than an equimolecular proportion of an aliphatic compound consisting of an 'alkyl group attached to a reactive halogen containing. group and blending a relativel'y'small amount of the thus formed condensation, product with the lubricating oil to be improved.

18. A lubricating oil containing a minor amount 0;, a ketonic condensation product formed by gbndensing substantially an equilnolecular proportion of an acyl'halide with a naphthenic compoundin the presence-of a Friedel Crafts condensing agent. a

. LOUIS A. MIKESKA. 

